package by.twouexplorer;


import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnCancelListener;

public final class AsyncTaskManager implements IProgressTracker, OnCancelListener {
    
    private final OnTaskCompleteListener mTaskCompleteListener;
    private final ProgressDialog mProgressDialog;
    private Copier mAsyncTask;

    public AsyncTaskManager(Context context, OnTaskCompleteListener taskCompleteListener) {
	// Save reference to complete listener (activity)
	mTaskCompleteListener = taskCompleteListener;
	// Setup progress dialog
	mProgressDialog = new ProgressDialog(context);
	mProgressDialog.setIndeterminate(true);
	mProgressDialog.setCancelable(true);
	mProgressDialog.setOnCancelListener(this);
    }

    public void setupTask(Copier asyncTask) {
	// Keep task
	mAsyncTask = asyncTask;
	// Wire task to tracker (this)
	mAsyncTask.setProgressTracker(this);
	// Start task
	mAsyncTask.execute();
    }

    public void onProgress(String message) {
	// Show dialog if it wasn't shown yet or was removed on configuration (rotation) change
	if (!mProgressDialog.isShowing()) {
	    mProgressDialog.show();
	}
	// Show current message in progress dialog
	mProgressDialog.setMessage(message);
    }

    public void onCancel(DialogInterface dialog) {
	// Cancel task
	mAsyncTask.cancel(true);
	// Notify activity about completion
	mTaskCompleteListener.onTaskComplete(mAsyncTask);
	// Reset task
	mAsyncTask = null;
    }
    
    public void onComplete() {
	// Close progress dialog
	mProgressDialog.dismiss();
	// Notify activity about completion
	mTaskCompleteListener.onTaskComplete(mAsyncTask);
	// Reset task
	mAsyncTask = null;
    }

    public Object retainTask() {
	// Detach task from tracker (this) before retain
	if (mAsyncTask != null) {
	    mAsyncTask.setProgressTracker(null);
	}
	// Retain task
	return mAsyncTask;
    }

    public void handleRetainedTask(Object instance) {
	// Restore retained task and attach it to tracker (this)
	if (instance instanceof Copier) {
	    mAsyncTask = (Copier) instance;
	    mAsyncTask.setProgressTracker(this);
	}
    }

    public boolean isWorking() {
	// Track current status
	return mAsyncTask != null;
    }
}